1. Field of the Invention
The present invention relates to a vertical axis wind turbine generator.
2. Description of the Related Art
Heretofore, there has been known a horizontal axis wind turbine generator, as shown in FIG. 14 and FIG. 15. In this horizontal axis wind turbine generator employing the conventional technique, a blade 102 is provided on the windward side of a rotating shaft 101 horizontally arranged, while a generator 103 is provided on the leeward side of the rotating shaft 101.
As this kind of horizontal axis wind turbine generator, there is publicly known a wind power generator in which a horizontal axis wind turbine generator is equipped with a generator main body, a power transmission shaft which is rotatably and horizontally supported and transmits a rotary motion to the generator main body, a plurality of spokes radially provided on the power transmission shaft, and blades supported by these spokes. Then, a plurality of protruding pieces provided in the spokes and the blades are coupled by a coupling shaft parallel to these spokes. Each of the blades freely sways around the coupling shaft between an angle made by allowing one end of each blade on a side of the coupling shaft to abut against the spoke for the blade to become oblique to a plane orthogonal to the power transmission shaft and an angle made by allowing each blade to become substantially perpendicular to this plane. Besides, this horizontal axis wind turbine generator includes a spring which is wound around the coupling shaft and is sandwiched in a compressed state so as to energize the blade in its closing direction between the spoke and the blade, as disclosed in, e.g., Japanese unexamined patent application publication No. H8-128385.
The horizontal axis wind turbine generator according to the foregoing conventional technique is designed so that its rotating shaft is parallel to a wind direction, and thus this type has to continue to be kept parallel to a wind direction generally fluctuating, thus requiring an orientation control mechanism.
In regard to this problem, the vertical axis wind turbine generator whose rotating shaft is perpendicular to a wind direction is usually installed so that its rotating shaft becomes perpendicular to the ground surface, and therefore wind always blows perpendicularly to the rotating shaft, leading to the advantage of requiring no orientation control.
Even in the vertical axis wind turbine generator, however, its blade operation must be stabilized, corresponding to a wind power in the same manner as in the horizontal axis wind turbine generator.
Conventionally, however, there has been no vertical axis wind turbine generator capable of stabilizing the behavior of its own blade according to a wind power, using a simple structure.